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18
Hierarchical Zbuffer visibility
 In Computer Graphics (SIGGRAPH ’93 Proceedings
, 1993
"... An ideal visibility algorithm should a) quickly reject most of the hidden geometry in a model and b) exploit the spatial and perhaps temporal coherence of the images being generated. Ray casting with spatial subdivision does well on criterion (a), but poorly on criterion (b). Traditional Zbuffer sc ..."
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Cited by 276 (1 self)
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An ideal visibility algorithm should a) quickly reject most of the hidden geometry in a model and b) exploit the spatial and perhaps temporal coherence of the images being generated. Ray casting with spatial subdivision does well on criterion (a), but poorly on criterion (b). Traditional Zbuffer scan conversion does well on criterion (b), but poorly on criterion (a). Here we present a hierarchical Zbuffer scanconversion algorithm that does well on both criteria. The method uses two hierarchical data structures, an objectspace octree and an imagespace Z pyramid, to accelerate scan conversion. The two hierarchical data structures make it possible to reject hidden geometry very rapidly while rendering visible geometry with the speed of scan conversion. For animation, the algorithm is also able to exploit temporal coherence. The method is well suited to models with high depth complexity, achieving orders of magnitude acceleration in some cases compared to ordinary Zbuffer scan conversion.
The Irradiance Volume
, 1996
"... This thesis presents a volumetric representation for the global illumination within a space based on the radiometric quantity irradiance. We call this representation the irradiance volume. Although irradiance is traditionally computed only for surfaces, its de nition can be naturally extended to all ..."
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Cited by 98 (8 self)
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This thesis presents a volumetric representation for the global illumination within a space based on the radiometric quantity irradiance. We call this representation the irradiance volume. Although irradiance is traditionally computed only for surfaces, its de nition can be naturally extended to all points and directions in space. The irradiance volume supports the reconstruction of believable approximations to the illumination in situations that overwhelm traditional global illumination algorithms. Atheoretical basis for the irradiance volume is discussed and the methods and issues involved with building the volume are described. The irradiance volume method is tested within several situations in which the use of traditional global illumination methods is impractical, and is shown to provide good performance.
Accelerating Volume Animation by SpaceLeaping
, 1993
"... f i In this paper we present a method for speeding the process of volume rendering a sequence o mages. Speedup is based on exploiting coherency between consecutive images to shorten the n path rays take through the volume. This is achieved by providing each ray with information eeded to leap over th ..."
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Cited by 75 (9 self)
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f i In this paper we present a method for speeding the process of volume rendering a sequence o mages. Speedup is based on exploiting coherency between consecutive images to shorten the n path rays take through the volume. This is achieved by providing each ray with information eeded to leap over the empty space and commence volume traversal at the vicinity of mean  b ingful data. The algorithm starts by projecting the volume into a Cbuffer (Coordinates uffer) which stores, at each pixel location, the objectspace coordinates of the first nonempty s t voxel visible from that pixel. For each change in the viewing parameters, the Cbuffer i ransformed accordingly. In the case of rotation the transformed Cbuffer goes through a pro  b cess of eliminating coordinates that possibly became hidden. The remaining values in the C uffer serve as an estimate of the point where the new rays should start their volume traverc sal. This spaceleaping method can be combined with existing accele...
Radiance Interpolants for Accelerated BoundedError Ray Tracing
 ACM Transactions on Graphics
, 1999
"... this paper, we present a system that exploits objectspace, rayspace, imagespace and temporal coherence to accelerate ray tracing. Our system uses persurface interpolants to approximate radiance, while conservatively bounding error. The techniques we introduce in this paper should enhance both int ..."
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Cited by 59 (6 self)
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this paper, we present a system that exploits objectspace, rayspace, imagespace and temporal coherence to accelerate ray tracing. Our system uses persurface interpolants to approximate radiance, while conservatively bounding error. The techniques we introduce in this paper should enhance both interactive and batch ray tracers.
Theory and Application of Specular Path Perturbation
, 2000
"... In this paper we apply perturbation methods to the problem of computing specular reflections in curved surfaces. The key idea is to generate families of closely related optical paths by expanding a given path into a highdimensional Taylor series. Our path perturbation method is based on closedform ..."
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Cited by 35 (3 self)
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In this paper we apply perturbation methods to the problem of computing specular reflections in curved surfaces. The key idea is to generate families of closely related optical paths by expanding a given path into a highdimensional Taylor series. Our path perturbation method is based on closedform expressions for linear and higherorder approximations of ray paths, which are derived using Fermat's Variation Principle and the Implicit Function Theorem. The perturbation formula presented here holds for general multiplebounce reflection paths and provides a mathematical foundation for exploiting path coherence in ray tracing acceleration techniques and incremental rendering. To illustrate its use, we describe an algorithm for fast approximation of specular reflections on curved surfaces; the resulting images are of high accuracy and nearly indistinguishable from ray traced images. Keywords: perturbation theory, implicit surfaces, optics, ray tracing, specular reflection 1 1 Introduct...
An Efficient SpatioTemporal Architecture for Animation Rendering
, 2003
"... Producing high quality animations featuring rich object appearance and compelling lighting effects is very time consuming using traditional framebyframe rendering systems. In this paper we present a rendering architecture for computing multiple frames at once by exploiting the coherencebetween i ..."
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Cited by 29 (3 self)
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Producing high quality animations featuring rich object appearance and compelling lighting effects is very time consuming using traditional framebyframe rendering systems. In this paper we present a rendering architecture for computing multiple frames at once by exploiting the coherencebetween image samples in the temporal domain.
BoundedError Interactive Ray Tracing
, 1998
"... Ray tracing, which computes radiance, is traditionally regarded as an offline rendering algorithm that is too slow for interactive use. In this paper, we present an interactive system that uses 4D interpolants to approximate radiance, while providing guaranteed error bounds. Our system exploits the ..."
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Cited by 11 (3 self)
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Ray tracing, which computes radiance, is traditionally regarded as an offline rendering algorithm that is too slow for interactive use. In this paper, we present an interactive system that uses 4D interpolants to approximate radiance, while providing guaranteed error bounds. Our system exploits the objectspace, rayspace, imagespace and temporal coherence in radiance to accelerate ray tracing. Our system explicitly decouples the two operations of the ray tracer  shading computation and visibility determination at each pixel, which we call pixel assignment. Rendering is accelerated by approximating the shading computation while guaranteeing correct pixel assignment. Without any preprocessing, the system lazily collects 4D radiance samples, which are quadrilinearly interpolated to approximate radiance. An error predicate conservatively guarantees that the relative error introduced by interpolation is bound by a userspecified ffl. The user can change this parameter to trade off pe...
Coherence in Computer Graphics
, 1992
"... Coherence denotes similarities between items or entities. It describes the extent to which these items or entities are locally constant. An introduction to coherence and a survey of various types of coherence, that are used in computer graphics, are given. Techniques and data structures for exploiti ..."
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Cited by 11 (1 self)
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Coherence denotes similarities between items or entities. It describes the extent to which these items or entities are locally constant. An introduction to coherence and a survey of various types of coherence, that are used in computer graphics, are given. Techniques and data structures for exploiting coherence in computer graphics are described. Incremental techniques, bounding volume schemes, subdivision techniques and several geometric data structures are discussed in more detail. Applications of coherence principles to computer graphics are treated and a survey of previous research is done. INTRODUCTION General remarks The widespread application of coherence principles allows only a vague definition of coherence. Without giving a formal definition coherence denotes, in the context of this paper, similarities between items or entities. It describes the extent to which these items or entities are locally constant. In many situations properties do not change drastically but rather in ...
Fast Ray Tracing of Sequences by Ray History Evaluation
, 1994
"... We present a method to reduce the time needed to render a sequence of ray traced images. We exploit the temporal and spatial coherence between consecutive frames. The algorithm does not only inspect the image plane in order to find regions with minor changes ..."
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Cited by 3 (0 self)
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We present a method to reduce the time needed to render a sequence of ray traced images. We exploit the temporal and spatial coherence between consecutive frames. The algorithm does not only inspect the image plane in order to find regions with minor changes